1 /** 2 * This file Copyright (c) 2003-2016 Magnolia International 3 * Ltd. (http://www.magnolia-cms.com). All rights reserved. 4 * 5 * 6 * This file is dual-licensed under both the Magnolia 7 * Network Agreement and the GNU General Public License. 8 * You may elect to use one or the other of these licenses. 9 * 10 * This file is distributed in the hope that it will be 11 * useful, but AS-IS and WITHOUT ANY WARRANTY; without even the 12 * implied warranty of MERCHANTABILITY or FITNESS FOR A 13 * PARTICULAR PURPOSE, TITLE, or NONINFRINGEMENT. 14 * Redistribution, except as permitted by whichever of the GPL 15 * or MNA you select, is prohibited. 16 * 17 * 1. For the GPL license (GPL), you can redistribute and/or 18 * modify this file under the terms of the GNU General 19 * Public License, Version 3, as published by the Free Software 20 * Foundation. You should have received a copy of the GNU 21 * General Public License, Version 3 along with this program; 22 * if not, write to the Free Software Foundation, Inc., 51 23 * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 24 * 25 * 2. For the Magnolia Network Agreement (MNA), this file 26 * and the accompanying materials are made available under the 27 * terms of the MNA which accompanies this distribution, and 28 * is available at http://www.magnolia-cms.com/mna.html 29 * 30 * Any modifications to this file must keep this entire header 31 * intact. 32 * 33 */ 34 package info.magnolia.cms.beans.config; 35 36 import java.util.Random; 37 38 import org.apache.commons.lang3.StringUtils; 39 import org.slf4j.Logger; 40 import org.slf4j.LoggerFactory; 41 42 43 /** 44 * <p> 45 * An extension of {@link RegexpVirtualURIMapping} that allows a rotation between different destination urls. In order 46 * to rotate <code>toURI</code> must contain the <code>*</code> that will be replaced by a random number between 47 * <code>start</code> (default is <code>1</code>) and <code>end</code> (defaults is <code>3</code>). 48 * </p> 49 * <p> 50 * An additional property <code>padding</code> can specify the left 0 padding for numbers (defaults is <code>2</code>). 51 * So for example a destination url like <code>forward:/banner/image_*.jpg</code> will randomly forward the request to 52 * <code>/banner/image_01.jpg</code>, <code>/banner/image_02.jpg</code> or <code>/banner/image_03.jpg</code> 53 * </p> 54 */ 55 public class RotatingVirtualURIMapping extends RegexpVirtualURIMapping { 56 57 private static final Logger log = LoggerFactory.getLogger(RotatingVirtualURIMapping.class); 58 59 /** 60 * Placeholder that will be replaced by a random number. 61 */ 62 private static final String RANDOM_PLACEHOLDER = "*"; 63 64 /** 65 * Lower bound for the generated random number. 66 */ 67 private int start = 1; 68 69 /** 70 * Upper bound for the generated random number. 71 */ 72 private int end = 3; 73 74 /** 75 * Left padding (using 0s). 76 */ 77 private int padding = 2; 78 79 /** 80 * Sets the start. 81 * 82 * @param start the start to set 83 */ 84 public void setStart(int start) { 85 this.start = start; 86 } 87 88 /** 89 * Sets the end. 90 * 91 * @param end the end to set 92 */ 93 public void setEnd(int end) { 94 this.end = end; 95 } 96 97 /** 98 * Sets the padding. 99 * 100 * @param padding the padding to set 101 */ 102 public void setPadding(int padding) { 103 this.padding = padding; 104 } 105 106 /** 107 * {@inheritDoc} 108 */ 109 @Override 110 public MappingResult mapURI(String uri) { 111 // delegate the initial processing to RegexpVirtualURIMapping 112 MappingResult mr = super.mapURI(uri); 113 114 if (mr != null) { 115 if (end > start) { 116 int randomNumber = new Random().nextInt(end - (start - 1)) + start; 117 String randomAsString = StringUtils.leftPad(Integer.toString(randomNumber), padding, '0'); 118 119 mr.setToURI(StringUtils.replace(mr.getToURI(), RANDOM_PLACEHOLDER, randomAsString)); 120 } else { 121 log.warn("End value must be greater than start value."); 122 } 123 } 124 return mr; 125 } 126 }